there is no simple answer to that due to just how many variables you have to account for. the most dumbed down answer i can give you is simply no. there is no amount of global effort that can be achieved to make the world the way it was even 10 or 20 years ago. species have gone extinct that previously had considerable impact on the environments they lived in. deforestation can never be undone due to the unbalance of the areas resources that was created as a result. and polar ice caps that have melted have no chance of refreezing.
but it is also important to realize that climate change and environmental destruction are two different things. we pollute the planet by covering it in our own waste, plastic garbage, and whatever else, and it is causing ocean life to suffer, and toxins that leak from the plastic will eventually poison affected environments and kill them. this could all be avoided if we stopped polluting and cleaned up our shit, it would just be very hard to do. climate change is simply a consequence of pollution that is causing climates and temperatures around the globe to change, which is already too late to try and stop, but it isnt 'necessarily' the worst thing ever. the earth will survive in whatever form if the temperature around the globe increases, although it would have higher water levels and species would evolve more to survive warmer climates. and again, thats not a bad thing in the long run, but the point of trying to prevent it is to so that we dont end up causing mass extinction of hundred of species. its all just to preserve the planet the way it is.
but the two have to come hand-in-hand. we need to clean up our shit to protect the environment, and we need to stop throwing gasses into the air to war up the planet any faster. and if we do that, we will survive, its just too late to go back to where we were 10 years ago